24 CELERY CULTURE 



izers are pure, and as a rule those containing the 

 higher percentages of the essential ingredients will 

 give the best results with a minimum amount of 

 labor and cost. In order to provide the required 

 weight without increasing the percentages of low 

 grade fertilizers it is often necessary to add a filler 

 consisting of ground rock, ground shells, or dry 

 earth. The filler itself has very little fertilizing 

 value, and its use entails considerable additional 

 cost for freight and handling. It has been shown 

 that celery requires an abundance of all forms of 

 plant food, and for this reason a high grade, com- 

 plete fertilizer should be employed. A ''complete" 

 fertilizer contains all three elements, potash, phos- 

 phoric acid, and nitrogen. To determine the value 

 of a ready-mixed fertilizer from the guaranteed 

 analysis printed upon the bags, multiply the per- 

 centages given by 20 to determine the number of 

 pounds of each in a ton, and multiply the product by 

 the current price of the element a pound. For 

 instance, if we have the following: 



Nitrogen . . . 4 per cent, x 20 = 80 pounds in a ton at 15 cents = $12 

 Phosphoric acid 6 per cent, x 20 = 120 pounds in* a ton at 5 cents = 6 

 Potash ... 5 per cent, x 20 = 100 pounds in a ton at 5 cents = 5 



Total actual value «... ^23 



The price usually charged by dealers for this class 

 of fertilizer is about $28, and freight charges must 

 be added in any case. As a rule the higher the grade 

 of fertilizer the lower will be the difference of ratio 



